The proliferation of smartphones has led to consumers increasingly carrying music collections with them. Speaker manufacturers have responded to this market trend by making smaller, portable wireless speakers and wireless multi-room speakers (e.g., Bluetooth portable speakers and multi-room Wi-Fi speakers). As the form factor of wireless speakers shrinks, the proportion of the enclosure occupied by the speaker element (e.g. the speaker cone and electromagnetic driver) has increased.
In a related area, a new generation of smart speakers (e.g. the Amazon Echo, the Google Home speaker and the Apple HomePod) combine music streaming with an interface to the World Wide Web and provide user control of smart building automation devices (e.g. smart lighting and smart televisions). User interfaces to smart speakers are an active area of innovation, due in part to the competing requirements for user controls (e.g. buttons and sensors) and large speaker elements in small enclosures.